This document provides information on air barrier design and testing for large buildings. It discusses how air barriers can reduce energy costs and improve occupant comfort by limiting air infiltration and exfiltration. Different air barrier designs are described for exterior envelopes and interior partitions. The document emphasizes that a properly designed, installed, and tested air barrier is essential but complex, requiring coordination between trades and quality assurance measures to ensure continuity and effectiveness of the air barrier. It recommends hiring experienced air barrier consultants to help with design, testing, and troubleshooting of large building air barriers.

1. Large Building Air Barrier Design and
Testing Services
7240 East Carter Road
Westmoreland, NY 13490
315 336-7955

2. An effectively designed and installed air
barrier system can:
• Reduce energy costs
• Increase building life
• Ensure occupant comfort
• Provide a healthier indoor environment
Why Air Barriers?

3. Air barriers may be installed on the exterior building
envelope to reduce infiltration and exfiltration…
Or
Installed on interior partitions, floors and ceilings to
prevent air movement from one part of the building to
another.
Different Air Barrier Designs for
Different Purposes

4. An exterior air barrier controls the flow of air through the
building envelope by sealing leaks, reducing infiltration
and exfiltration. The photos to the right show two
different approaches.
The upper photo illustrates a black spray-applied fluid
membrane on concrete masonry walls. The blue self-adhering
membrane at the corners and windows and doors prevent air
leaks at those locations. The membrane will also be applied to
the soffit and fascia to connect the roof air barrier membrane
to the wall air barrier.
The air barrier system in the lower photo consists of a four-
inch layer of polyisocyanurate foam insulation sprayed on
exterior gypsum sheathing. Windows and doors will also be
sealed with a self-adhering membrane. In this facility the
interior ceiling will be the air barrier. Special attention is need
to connect the wall air barrier to the ceiling air barrier.
How Do Air BarriersWork?

5. An interior air barrier works much the same way as an exterior barrier.
Leaks between different parts of the building are sealed, preventing air
from moving from one part of the building to another. This is particularly
useful in townhouses, apartment buildings, dormitories and hotels for
preventing odors from moving from one unit to another.
Owners of manufacturing facilities also find interior air barrier useful for
preventing airborne contaminants from the manufacturing floor from
migrating to the office and administration spaces.
A properly designed and installed air barrier can also serve as a smoke and
fire boundary in locations where those type partitions are required.
Interior Air Barriers

6. An Effective Air Barrier Must:
• Be continuous over the entire boundary area
• Be impervious to air flow
• Be able to withstand forces applied to them during
and after construction
• Last the expected life of the building.
A Proper Design is Essential

7. Continuity FromTop to Bottom
Self-adhering membrane serves as
roof air barrier.
Fluid applied air barrier on plywood
sheathing. All joints in sheathing
primed and taped.
Self-adhering membrane serves as
transition between plywood sheathing and
roof air barrier. Do not weld overhang to wall
framing.

8. Self-adhering membrane
connects window to fluid-
applied membrane
Self-adhering membrane
connects window to fluid-
applied membrane
Window is part of air
barrier system
Self-adhering membrane roof
air barrier
connects to fluid-applied on
wall

9. Cast-in-Place foundation serves as wall air
barrier. All joints and penetrations sealed.
Concrete slab serves as floor air barrier.
All joints and penetrations sealed.
Joint filler connects floor to wall
air barrier

10. Remember:
• Someone may design it but someone else has to build it.
Make sure it is buildable!!!
• Air barrier installation can interfere with the “typical”
construction sequence.
• The materials must be rated as an air barrier material –
check the specs and submittals carefully.
• It must be able to withstand forces applied to it:
• Wind, rain, sunlight, deflection, etc.
• It has to last the life of the building
The Concept Looks Simple
BUT IT IS NOTTHAT EASY

11. Typically, different parts of the air barrier are installed by
different trades. All involved with the installation must
coordinate with each other.
• Insulation contractor
• Masons
• Window contractor
• Roofing contractor
Trades not involved with the installation must know that if
they put a hole through the air barrier it must be sealed.
Installing the Air Barrier

12. Each trade, either involved with the air barrier installation or not
must be aware of the air barrier and its location. Each trade must
be responsible for maintaining the integrity of the air barrier.
The Prime Contractor must assign a QA person to inspect the air
barrier daily. If subsequent work makes a penetration through
the air barrier, it must be sealed AND inspected before it is
covered.
Many Prime Contractors (or building owners) will hire a third
party consultant to conduct scheduled and/or sometimes
unannounced additional inspections.
Quality Assurance

13. Determining if an effective air barrier has been designed
and installed correctly can take different approaches:
• Blind trust in the design and installation. “Of course it
works, a registered architect designed it and all the
trades involved had the right certificates”.
• Performance testing to meet a specific air tightness
target. “Waddaya mean it has to be tested”?
Does itWork and How Do We Know?

14. It happens. Quite often an air barrier is required by
the specifications but there is no requirement to make
sure it actually functions properly.
This is changing because architects, prospective
building owners and Prime Contractors are beginning
to understand the value of designing and installing
an effective air barrier AND testing to determine its
performance.
BlindTrust

15. Testing to determine the air barrier effectiveness is now required in many instances:
• The U.S. Army Corps of Engineers requires a continuous air barrier be designed, installed and
tested in all new buildings under their cognizance.
• LEED Multifamily ETS PR 2012. This is an Indoor Environmental Quality prerequisite for all
LEED Multifamily buildings and is intended to reduce Environmental Tobacco Smoke transfer
between units. The standard requires testing individual units and leakage must be less than
0.23 CFM50/ ft2 unit enclosure.
• The 2012 International Energy Conservation Code (IECC) requires testing of multifamily
buildings less than 3 stories.
• The General Services Administration (GSA) requires testing of new government buildings.
• Washington State requires that commercial and multifamily residential buildings of greater
than five stories have the completed air barrier tested
Air BarrierTesting

16. Testing is usually conducted using calibrated blower doors in accordance with StandardTest Methods
developed by ASTM and USACE.
The USACE “”U.S. Army Corps of Engineers Air LeakageTest Protocol for Building Envelopes” is
quickly becoming the standard test method for testing large buildings. This standard presents
methods for testing large building adapted from ASTM standards and developed by USACE personnel
and Industry Consultants.
The USACE Protocols requires building envelopes have a leakage rate that does not exceed 0.25 cubic
feet per minute of leakage per square foot of air barrier area (cfm/sq. ft.) at an indoor/outdoor
pressure difference of 75 Pascals (0.3 in. w.g.).
Note: As many of the USACE buildings constructed under this requirement have met or bettered the
target air tightness USACE is beginning to required building meet a target air tightness of 0.15 cfm/sq.
ft.
Testing and Scoring the Air Barrier

17. Usually conducted using blower doors.
• Temporarily install blower doors in exterior
doorways of the facility.
• Supply outdoor air to the building (a
pressurization test)
• Exhaust air from the building (a
depressurization test)
• Use the results of these tests to calculate the
air leakage rate.
Testing
A multiple fan blower door system. Large
buildings may require several blower door
systems deployed around the facility to
achieve the required indoor/outdoor pressure
difference.

18. If you are looking for an Air Barrier Consultant to help with your large
building project consider these items:
• Do they have demonstrated large building experience?
• Can they help with the air barrier design?
• Do they have the proper test equipment?
• If the air barrier does not function as intended do they have the experience and
knowledge to determine the problem and solution?
Make sure you hire the people who can do the job right – the first time.
Once Again, It Isn’t As Easy As It
Sounds

19. Camroden Associates, Inc.
7240 E. Carter Rd.
Westmoreland, NY 13490
315 336-7955
www.camroden.com
Give Us A Call –We
Can Help